The present invention concerns nonwoven materials mainly for use in personal care products like diapers, training pants, swim wear, absorbent underpants, adult incontinence products and feminine hygiene products. This material may also be used other applications such as, for example, in bandages and wound dressings, nursing pads and in veterinary and mortuary applications.
Personal care articles usually have multiple layers of material of some sort to absorb liquids from the body. These layers may include natural fibers, synthetic fibers and superabsorbent particles in varying proportions. When liquid such as urine is deposited into a personal care product like a diaper, it goes through the uppermost layers, typically a liner positioned against the body and a xe2x80x9csurgexe2x80x9d layer designed to provide temporary liquid hold-up. The product may also have a xe2x80x9cdistributionxe2x80x9d layer designed to move liquid in the X and Y directions in order to utilize more of the absorbent core. After going through these upper layers, the urine enters the absorbent core portion of the product. The absorbent core permanently retains the liquid. Absorbent cores are typically composed of superabsorbent particles or mixtures of superabsorbent particles and pulp.
The conformability and comfort of the personal care product is an important matter for wearers. Personal care products should be able to move with the wearer without falling off or becoming entangled. They should not stretch (without recovery) to the point where waste material may escape from the diaper. Past materials for personal care products have included superabsorbents, generally as particles. These particles may move relatively independently as a garment is stretched and so do not impede the wearer""s movement. They also require containment of some sort to prevent them from falling out of the product or coming in contact with the wearer""s skin. While superabsorbent particles do not significantly reduce the elasticity of a personal care product, neither do they contribute to it. As a result, other components of the personal care product must provide the necessary elasticity. The end result is a personal care product that is no doubt bulkier than it could be if the superabsorbent also contributed in some way to the elasticity of the product.
It would be very desirable to have one material having absorbency and elastic properties so that personal care products may be made less bulky and more simple to construct. Such a material would also avoid the undesirable feature of superabsorbent particle leakage from the product since it would not be in particulate form. There remains a need, therefore, for a superabsorbent that will have good elastic properties and provide absorbent properties in the recesses of the body.
In response to the discussed difficulties and problems encountered in the prior art, a new material for use in personal care products has been discovered, where the material is made from an elastic acrylate-containing polymer which is extruded and is dimensionally stable and superabsorbent. The elastic polymer maybe extruded as a fiber, film, foam, fibrous film or fibrous foam. The extruded polymer may be mixed with pulp and/or synthetic fibers, particles (and mixtures thereof) to produce a layer having various predetermined amounts of superabsorbent and other fibers. One way of making the polymer for use in this inventions is by reacting an amine or hydroxy terminated polyether polyol with water and an isocyanate like isophorone di-isocyanate or toluene di-isocyanate.
The polymer layer may be stabilized by cross-linking it with a high energy beam such as an electron beam or an ultra-violet beam.
The layer of this invention is useful in personal care products like diapers, training pants, incontinence products, bandages, sanitary napkins and the like.